\tracingonline=2
\tracingcommands=2
\tracingmacros=2
\tracingrestores=2

\count10=20
\advance\count10 30
\showthe\count10

% spaces and by
\count10=20
\advance  \count  10  20
\showthe\count10

\advance  \count  10  by 20
\showthe\count10

\advance  \count  10by20
\showthe\count10

% dimen
\dimen0=10.5pt
\advance\dimen0by0.4pt
\showthe\dimen0

\advance\dimen0by0.1pt
\showthe\dimen0

\advance\dimen0by"3FFFFFFFsp
\showthe\dimen0

\count1="7FFFFFFF
\advance\count1by1
\dimen1=1\count1
\showthe\dimen1

% skip
\skip0=10.5pt
\advance\skip0by0.4pt
\showthe\skip0

\advance\skip0by0.1pt
\showthe\skip0

\skip0=10.5pt plus 3pt minus 4pt
\advance\skip0by0.4pt
\showthe\skip0
\advance\skip0by0.4pt plus 5pt
\showthe\skip0
\advance\skip0by0.4pt plus 7pt minus 3pt
\showthe\skip0
\advance\skip0by0.4pt plus 3fill minus 3fil
\showthe\skip0
\advance\skip0by0.4pt plus 5fil minus 5filll
\showthe\skip0

\skip0=10.5pt plus 3fil minus 4fil
\advance\skip0by0.4pt
\showthe\skip0
\advance\skip0by0.4pt plus 5pt
\showthe\skip0
\advance\skip0by0.4pt plus 7pt minus 3pt
\showthe\skip0
\advance\skip0by0.4pt plus 3fill minus 3fil
\showthe\skip0
\advance\skip0by0.4pt plus 5fil minus 5filll
\showthe\skip0

\advance\skip0by"3FFFFFFFsp
\showthe\skip0

\count1="7FFFFFFF
\advance\count1by1
\skip1=1\count1
\showthe\skip1

% muskip
\muskip0=10.5mu
\advance\muskip0by0.4mu
\showthe\muskip0

\advance\muskip0by0.1mu
\showthe\muskip0

\muskip0=10.5mu plus 3mu minus 4mu
\advance\muskip0by0.4mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 5mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 7mu minus 3mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 3fill minus 3fil
\showthe\muskip0
\advance\muskip0by0.4mu plus 5fil minus 5filll
\showthe\muskip0

\muskip0=10.5mu plus 3fil minus 4fil
\advance\muskip0by0.4mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 5mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 7mu minus 3mu
\showthe\muskip0
\advance\muskip0by0.4mu plus 3fill minus 3fil
\showthe\muskip0
\advance\muskip0by0.4mu plus 5fil minus 5filll
\showthe\muskip0

\advance\muskip0by"3FFFFFFFsp
\showthe\muskip0

\count1="7FFFFFFF
\advance\count1by1
\muskip1=1\count1
\showthe\muskip1


% overflow (TeX do not checks for it!)
\count0="7FFFFFFE
\showthe\count0
\advance\count0 2
\showthe\count0
\advance\count0 2
\showthe\count0

% errors
\advance\par\relax

\count0=10
\advance\count0by\relax
\showthe\count0

\end
